1. Field of the Invention
The present invention relates to a gear product including a set of coaxial gear members which have different tooth profiles and configurations and are formed continuously without any clearance therebetween to be adjacent to each other directly or via a flange. An example of such gear product includes a gear component having synchronous clutch spline teeth used for a transmission mechanism.
2. Description of Related Art
Such gear product is typically manufactured according to either of the following two methods: (1) combining or joining separately forged plural gear members; and (2) forging gear material into an integral body consisting of plural gear members. In either method, tooth arrangements on the gear members are generally formed and finished by machining although part of the teeth may be formed through forging process. Especially, spiral tooth profile of a helical gear can not be formed by forging and should always be formed by machining.
The gear product manufactured by the above method (1) has several drawbacks as below:
(a) Manufacturing processes are rather complicated; PA1 (b) The yield is unfavorably low; and PA1 (c) It is substantially impossible to make the gear product compact and light in weight since each gear member is manufactured to have a required strength.
When teeth on the gear member are formed through machining, the proper fiber structure of gear material is undesirably cut off at the machined part to decrease the strength thereof. Machining the gear member requires a sufficient clearance on either side of its tooth arrangement to receive a machining tool and complete the machining, thus preventing the whole gear product from being made compact and light in weight. Teeth formed through machining further requires chamfering process.
There has, accordingly, been a strong demand for a gear product including plural gear members manufactured integrally by forging. Such demand has, however, not been realized due to some technological difficulties. In other words, conventional forged gear products including plural gear members are not of practical use.